The National Transportation Safety Board today urged the U.S. Department of Transportation to prohibit the carriage of hazardous materials in vulnerable piping, such as loading lines, of cargo tank trucks. The recommendation is contained in the Board's final report of a fatal tank truck/automobile collision in Yonkers, New York last year.
On October 9, 1997, shortly after midnight, a gasoline cargo tank truck was struck by an Eagle Premier sedan under an overpass of the New York Thruway in Yonkers, New York. The car hit the right side of the cargo tank in the area of the tank's external loading lines, releasing the gasoline they contained. The ensuing fire destroyed both vehicles and the overpass, and the car driver was killed. The Thruway remained closed for approximately 6 months. Damage was estimated at $7 million.
The Board determined that the crash was caused by the failure of the car driver to stop for a red light, reduce his speed or apply his brakes soon enough to avoid the collision.
The NTSB said that the significant element of this crash is not its cause so much as its severity. A similar error on the car driver's part might have had far less serious consequences. "The crucial difference," the Board stated, "was the presence of gasoline in the loading lines."
When the car struck the side of the truck, it ruptured the unprotected loading lines, allowing the release of up to 28 gallons of gasoline, much of which poured into the automobile and ignited. Five months after this crash, the Board investigated a similar accident in Wilmington, Delaware, in which 12 gallons of gasoline spilled from loading lines. Unlike Yonkers, though, the car driver was killed by the impact, not the ensuing fire.
Safety Board investigators demonstrated the vulnerability of loading lines by placing 12 different passenger car models near the loading lines of a cargo tank truck. The investigators found that each of the 12 vehicles would have struck the loading lines of the truck. Therefore, the Board believes that most vehicles currently in use are capable of striking the loading lines of cargo tanks.
In 1985, the Research and Special Programs Administration (RSPA) of the U.S. Department of Transportation (DOT), which regulates hazardous materials transportation, proposed a rule that would have required increased bottom accident damage protection for cargo tanks. When the regulations were actually amended 5 years later, the rulemaking permitted carriers to continue to transport petroleum products and other hazardous materials in loading lines without bottom damage protection. These loading lines can hold as much as 50 gallons of product.
Although statistics in this area are not complete, DOT data shows that between January 1990 and August 1997, 47 accidents involving such cargo tanks resulted in loading line failures caused by impact. Although it is difficult to know how many cargo tanks have this design, in 1984, a study done for the DOT estimated that there were about 58,000 MC-306 cargo tanks (with vulnerable loading lines). The Board believes the current number is larger than that. However, DOT is unable to accurately calculate how many there are.
The Board reiterated a recommendation it had issued to DOT in 1992 calling for a data collection program that would permit regulators to identify patterns of cargo tank equipment failures. Because of a lack of action on this recommendation by the DOT in the last 6 years, the NTSB classified this recommendation "Open – Unacceptable Response."
Stating that transporting hazardous materials in these lines "creates a hazardous condition," the Board recommended that the Secretary of Transportation prohibit the carrying of hazardous materials in external piping of cargo tanks, such as loading lines, that may be vulnerable to failure in an accident.
The NTSB's complete report on the Yonkers, New York accident, PB98-916202, may be purchased about a month from now from the National Technical Information Service, 5285 Port Royal Road, Springfield, Virginia 22161, (703) 487-4650.